It is necessary to tie a thin piece of gauze over the flower to be fertilized, before and after crossing, to prevent insects from conveying pollen to it, thus frustrating the labors of the operator. If the operation has been successful, the pistil will soon begin to wither; if not perfect, the pistil will continue fresh and full for some days. This _modus operandi_ is substantially the same in crossing fruits, flowers, and vegetables throughout the vegetable kingdom. Hybridizing differs from cross-breeding only in fertilizing one species, or one of its varieties, with the pollen of another species, or one of its varieties, of the same or a different _genus_. The offspring is called a hybrid, or mule. Hybrids, with very few exceptions, are sterile, they fail to propagate themselves from seed, and must, to preserve them, be propagated by grafts, layers, or suckers. No change is perceptible in the fruit produced from blossoms upon which the operation of cross-breeding or hybridizing has been performed; but the seed of fruits so obtained may be planted with the certainty of producing a fruit or tuber commingling the qualities, colors, and main characteristics of both parents. Experience, however, shows that the characteristics of the male predominate somewhat in the offspring. To judicious cross-breeding and hybridizing we owe most of our superior fruits and vegetables. If the operation were more generally known and practiced by farmers, the most gratifying results would be soon obtained, not only in the production of the most valuable varieties of potatoes and other vegetables, but also in fruits, flowers, and grain of every description. SMOOTH VS. ROUGH POTATOES. Other things being equal, smooth potatoes are preferable to those with deeply-sunken eyes. The starch being most abundant near the skin, not so much is lost by the thin paring of the former as by the necessarily deeper paring of the latter. Varieties usually well formed sometimes grow so knobby and ill-shaped as to be scarcely recognized. This is caused by severe drought occurring when the tubers are about two thirds grown, causing them to partially ripen. On the return of moisture, a new growth takes place, which shows itself in knobby protuberances. CUT AND UNCUT SEED. Many growers argue that potatoes should be planted whole. The only plausible theory in support of whole seed is, that the few eyes that do start have a greater supply of starch available from which to obtain nutriment until the plant can draw support from the soil and atmosphere. But experiments also demonstrate that if all the eyes except one or two near the middle be cut out of the seed-potato, such seed will push with the greatest possible vigor.